Taking the shoe as a concrete example, we present an innovative product retrieval system that leverages object detection and retrieval techniques to support a brand-new online shopping experience in this article. The system, called Circle & Search, enables users to naturally indicate any preferred product by simply circling the product in images as the visual query, and then returns visually and semantically similar products to the users. The system is characterized by introducing attributes in both the detection and retrieval of the shoe. Specifically, we first develop an attribute-aware part-based shoe detection model. By maintaining the consistency between shoe parts and attributes, this shoe detector has the ability to model high-order relations between parts and thus the detection... performance can be enhanced. Meanwhile, the attributes of this detected shoe can also be predicted as the semantic relations between parts. Based on the result of shoe detection, the system ranks all the shoes in the repository using an attribute refinement retrieval model that takes advantage of query-specific information and attribute correlation to provide an accurate and robust shoe retrieval. To evaluate this retrieval system, we build a large dataset with 17,151 shoe images, in which each shoe is annotated with 10 shoe attributes e.g., heel height, heel shape, sole shape, etc.). According to the experimental result and the user study, our Circle & Search system achieves promising shoe retrieval performance and thus significantly improves the users' online shopping experience.